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<p class='vspace'></p><h2>Integer Constants</h2>
<p>Integer constants are numbers used directly in a sketch, like <code>123</code>.  By default, these numbers are treated as <a class='wikilink' href='Int.html'>int</a>'s but you can change this with the U and L modifiers (see below).
</p>
<p class='vspace'></p><p>Normally, integer constants are treated as base 10 (decimal) integers, but special notation (formatters) may be used to enter numbers in other bases.  
</p>
<p class='vspace'></p><pre>
Base               Example    Formatter        Comment

10 (decimal)           123    none

2 (binary)        B1111011    leading 'B'      only works with 8 bit values (0 to 255)
                                               characters 0-1 valid

8 (octal)             0173    leading "0"      characters 0-7 valid       

16 (hexadecimal)      0x7B    leading "0x"     characters 0-9, A-F, a-f valid    

</pre>
<p class='vspace'></p><p><strong>Decimal</strong> is base 10. This is the common-sense math with which you are acquainted. Constants without other prefixes are assumed to be in decimal format.
</p>
<p class='vspace'></p>Example:<pre>
101     // same as 101 decimal   ((1 * 10^2) + (0 * 10^1) + 1)
</pre>
<p><br />
<strong>Binary</strong> is base two.  Only characters 0 and 1 are valid. 
</p>
<p class='vspace'></p>Example:<pre>
B101    // same as 5 decimal   ((1 * 2^2) + (0 * 2^1) + 1)
</pre>
<p>The binary formatter only works on bytes (8 bits) between 0 (B0) and 255 (B11111111). If it is convenient to input an int (16 bits) in binary form you can do it a two-step procedure such as:
</p>
<p class='vspace'></p><pre>
myInt = (B11001100 * 256) + B10101010;    // B11001100 is the high byte

</pre>
<p class='vspace'></p><p><strong>Octal</strong> is base eight.  Only characters 0 through 7 are valid. Octal values are indicated by the prefix "0"
</p>
<p class='vspace'></p><p>Example:
</p><pre>
0101    // same as 65 decimal   ((1 * 8^2) + (0 * 8^1) + 1) 
</pre><div class='indent'>Warning
</div><div class='indent'>It is possible to generate a hard-to-find bug by (unintentionally) including a leading zero before a constant and having the compiler unintentionally interpret your constant as octal.
</div><p><br />
<strong>Hexadecimal (or hex)</strong> is base sixteen. Valid characters are 0 through 9 and letters A through F; A has the value 10, B is 11, up to F, which is 15. Hex values are indicated by the prefix "0x". Note that A-F may be syted in upper or lower case (a-f).
</p>
<p class='vspace'></p><p>Example:
</p><pre>
0x101   // same as 257 decimal   ((1 * 16^2) + (0 * 16^1) + 1)

</pre>
<p class='vspace'></p><h4>U &amp; L formatters</h4>
<p>By default, an integer constant is treated as an <a class='wikilink' href='Int.html'>int</a> with the attendant limitations in values.  To specify an integer constant with another data type, follow it with:
</p>
<p class='vspace'></p><ul><li>a 'u' or 'U' to force the constant into an unsigned data format. Example: <code>33u</code>
</li><li>a 'l' or 'L' to force the constant into a long data format. Example: <code>100000L</code>
</li><li>a 'ul' or 'UL' to force the constant into an unsigned long constant. Example: <code>32767ul</code> 
</li></ul><p><br />
</p>
<p class='vspace'></p><h4>See also</h4>
<ul><li><a class='wikilink' href='Constants.html'>constants</a>
</li><li><a class='wikilink' href='Define.html'>#define</a>
</li><li><a class='wikilink' href='Byte.html'>byte</a>
</li><li><a class='wikilink' href='Int.html'>int</a>
</li><li><a class='wikilink' href='UnsignedInt.html'>unsigned int</a>
</li><li><a class='wikilink' href='Long.html'>long</a>
</li><li><a class='wikilink' href='UnsignedLong.html'>unsigned long</a>
</li></ul><p class='vspace'></p><p><a class='wikilink' href='index.html'>Reference Home</a>
</p>
<p class='vspace'></p><p><em>Corrections, suggestions, and new documentation should be posted to the <a class='urllink' href='http://forum.43oh.com/forum/28-energia/' rel='nofollow'>Forum</a>.</em>
</p>
<p class='vspace'></p><p>The text of the Energia Reference is licensed under a
<a class='urllink' href='http://creativecommons.org/licenses/by-sa/3.0/' rel='nofollow'>Creative Commons Attribution-ShareAlike 3.0 License</a>.  Energia reference is based on Arduino reference.  Code samples in the reference are released into the public domain.
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